Draft regulator



March 12, 1940. c; EKMAN 2,193,274

DRAFT REGULATOR Filed March 15, 1937 2 Sheets-Sheet l Mi 1 #1 A?! @i,

I I I ILEfIFT'f Lib farmer March 12, 1 940. A. c. EKMAN DRAFT REGULATOR Filed Match 15, 1937 2 Sheets-Sheet 2 Patented Mar. 12, 1940 UNITED STATE t tan 2' Claims.

This invention relates to a draft regulating means and While the invention might have variousapplications, it particularly is designed for use in a conduit extending from a combustion B chamber or furnace (either of the domestic or industrial type) to a chimney.

It is desirable to have a uniform draft in the smoke pipe leading from a furnace. This is rarely obtained as the draft through the smoke pipe is varied by many factors including the atmospheric conditions, such as the movements and pressure of the atmosphere. The draft is also varied by the combustion in the furnace. It is often desired to check the draft and this has been 15 commonly done by opening a check damper which permits air from the furnace room to pass intothe smoke pipe and out of the chimney. This constant drain of air from the furnace room is inefficient as the air is heated and allowed to pass 90 up the chimney and is replaced in the furnace room by cold air usually coming from the outside.

It is an object of this invention to provide a '85 function as desired in case of any back draft through the smoke pipe.

It isstill another object of the invention to provide a draft regulating means adapted to regulate the draft through the smoke pipe and 40 which will prevent gases passing into the furnace room therethrough should any unusual pressure develop in the furnace, such as might be caused by an explosion.

These and other objects and advantages of the invention will be fully set forth in the following description made in connection with the accompanying drawings in which like reference characters refer to similar parts throughout the several views and in. which- 50 Fig. 1 is a perspectiveview of a device embodying the invention;

Fig. 2 is a vertical central longitudinal section through the device;

Fig. 3 is a perspective view of a damper and a portion of a vane used;

Fig. 4 is a view in front elevation as seen from the left of Fig. 1; v

Fig. 5 is a vertical section taken substantially on line 5-5 of Fig. 2, as indicated by the arrows;

Fig. 6 is a view in side elevation of a modi- 6 fication; and Fig. '7 is a vertical section taken on line '!-1 of Fig. 6, as indicated by the arrows.

Referring to the drawings, a conduit ll! is shown and while this could be any conduit in which it is desired to regulate the draft or passage of air, it will be particularly referred to as the smoke pipe which connects a furnace to a chimney. Conduit H1 is adapted to be connected to a furnace at its left hand end as shown in Figs. 1 and 2 and to a chimney at its right hand end so that the gases pass therethrough in the a direction of the arrows shown in Fig. 2. Conduit it! is shown as crimped at one end lllb to form aspigot to be inserted in a smoke pipe. The conduit I0 is shown as having a downwardly extending portion Illa and a casing l i is provided having vertical side walls Ha which extend at their lower ends to the center of conduit Hi and are vertically alined with the sides of said conduit so that casing l l is of the same width as conduit. Ill. The front end of casing H is in a vertical plane passingthrough the lower end of portion Illa; Casing I l is open at its front or left hand end above conduit I0 save for a plate I2 which abuts the front edges of side walls Ma and of the top and rear wall I lb. It will be noted that wall I lb curves downwardly and rearwardly from the front of casing H ina substantially semi-cylindrical form to conduit l ll as clearly shown in Figs. 1 and 2. Plate 52 has an opening l2a therein and while this might take various forms, in the embodiment of the invention illustrated it is shown as substantially semi-circular. A plate I3 engages the front of plate I2 and is also of semi-circular form and is adapted to be moved to cover or partially cover opening A headed bolt M- extends through plate [2 and through plate l3 substantially at the center of the peripheral arc of the latter and is equipped with a nut I5 and washer iii. A compression coiled spring ll surrounds bolt i l between washer l6 and plate It so that the latter is resiliently held against plate l2. Plate It will thus have considerable friction against plate l2 and will be held in the position to which it is moved. Plate 1 2 has its lower edge resting on conduit in at the lower end of portion la and is held in position by resilient or spring members l8. Plate l2 has a narrow outwardly projecting flange H2!) at either side thereof and there is one of the members H8 at each side of plate l2. Member Hi which is made of a small resilient rod or wire has one end portion secured to the front of plate l2. Said end has a portion Illa which extends upwardly along the outer side of flange 120., then inwardly through said flange and along the front of plate til, then downwardly at a right angle for a short distance at portion i817, then outwardly at a right angle and again through flange lZa, the end being bent around portion its. Portion its at its lower end is bent rearwardly or to the right as shown in Figs. 1 and 2 and formed into a circular coil lllc, the end thereof then passing rearwardly along the outer side of side portion Ha of the casing and is provided with a bend or hook Hid.

passing through one flange of a small angle bar it which extends in a substantially radial direction along the side of casing l! and acts to stiffen the same. Portion lllb is secured to plate I! by a small clip we passing around portion 95b and through plate l2. With this structure it will be seen that plate I2 is held against the front of easing l l but swing away from said casing about an axis extending substantially along its lower edge by flexing of the members l8. A vane 23 is provided disposed in casing l l and said vane is substantially rectangular in form having straight side edges disposed quite closely to the inner sides of side portions Ma and having a straight top edge which moves quite closely to wall lb. Vane 29 is mounted for swinging movement about the axis of a pintle or pivot member 2! formed of a small rod or wire having portions Elaextending through apertures in side walls 8 Ila. Member 2} is curved upwardly across the lower portion of vane ill and secured to said vane centrally thereof by a small clip 22 bolted or riveted to vane 2&3. Vane 28 at its lower portion is formed into a curve extending around member 2! adjacent portions 2m and is continued to form a damper 29a, extending at an obtuse angle thereto. Damper 263a is shaped as shown in Fig. 3 and when moved to a position substantially perpendicular to the axis of conduit Ill will largely cut off the passage of air therethrough. Small reinforcing plates 29?) are secured to vane 2i and damper'Zila. Member 2| at one side of easing H has a portion extending rearwardly and said portion is then bent reversely to extend forwardly and downwardly in portion 2lc. Portion 2E0 has a weight 25 slidable thereon and which may be held in any desired position by thumb screw 2 2. With the described structure it will be seen that weight 23 tends to swing vane 20 in a counterclockwise direction. A small clip 25 is secured to the inner side of Wall Ha adjacent the front thereof, the same having a small inwardly bent flange the which will be padded and act as a stop member and with which vane 28 may engage. Narrow plates 26 of substantially rectangular form extend along the inner sides of the side walls Ha adjacent the top of conduit It, the same having small downwardly extending flanges engaging side walls Ma and small rods 2i extend diagonally across the underside of plates through flanges 25a. and walls Ila and are equipped with nuts 28 at the outer sides of walls lid. A rod Zia extends between side walls Ha adjacent plates 2%. Rods 21 act to maintain casing H in its proper form and rod 27a holds side walls lla properly spaced. Plates 26 have bentup portions or ribs 26b adjacent their ends adapted to be engaged. by vane 20 so that plates 26 limit the lower movement of vane 20.

In Figs. 6 and '7 a modified form of the invention is shown. With this modification the casing ll is formed as a separate unit from conduit Ill and has front and rear semi-circular portions ild which fit over and rest upon a smoke pipe 33, which smoke pipe is cut away at its top and sides along the line 39a. Portions l'ld have outwardly extending flanges He at their lower sides and are adapted to be secured to smoke pipe or conduit Bill by the curved bands or clips 3! fitting around conduit 38 and having flanges am at their upper ends engaging flanges He and secured thereto by the headed and nutted bolts Members 3i have downwardly extending flanges 3th at their lower ends which are connected by headed and nutted bolts 33. In all other respects the parts shown in Figs. 6 and '7 are identical with those already described and shown in Figs. .1 to 5.

In operation, with the conduit I!) connected as described, the weight 23 will be adjusted to hold the damper 2130 in the desired position for the gases to pass throughsmoke pipe 10. tion will vary with different installations. Plate it will be moved to position to give the desired amount of opening in opening lZa. With the normal draft or the gases passing through conduit ill as desired, damper 28a. and vane 20 will maintain substantially the positions for which they are set. Should a stronger draft occur toward the chimney, this will cause vane 20 to in clockwise direction since the draft tends to draw in air through opening 12a. Very little air can pass vane 29 as it moves quite close to the walls of casing l l. When vane 20 thus swings in a clockwise direction damper 20a is swung downwardly toward position to shut off the draft through conduit Ill. The increased draft in, the chimney, therefore, ,does not cause an increased draft through the furnace. If vane til is drawn all the way down to the stop member 26 damper 28a is substantially perpendicular to the axis of conduit iii and there is a maximum shutoif'of this conduit. The amount of this shutoii depends on the shape of damper 20a and as shown in Fig. 3 the damper-does not completely close the passage through conduit Ill. It will thus be seen that the draft through the furnace is checked and at the same time very little air is taken from the furnace room. There is hence not a continual drain of air from the furnace room in order tocheck the draft in the furnace. The device is quite sensitive and when connected in a smoke pipe it acts very frequently. The plate and regulation of opening 12a is provided to make the device somewhat less sensitive and to act as a stabilizer. Plate [3 can be adjusted to attain the desired response for-vane 20. It should be noted that if there is any excessive pressure outwardly or toward the chimney in conduit it it will swing damper 20 upwardly and can have a free outlet. Should there be any back pressure from the chimney or into the chimney end of conduit til it will act to swing vane in a counterclockwise direction. The back draft can be relieved by passing into casing l and if sufficient it will swing plate 12 outwardly against the tension of members l8. As soon as the pressure is relieved plate l2 will be moved bacl: against casing l2. Ribs 251) are provided so that plate it will not lie flat against'plates 26 and have a tendency to hold said plates by suction.

With the form shown in Fig. 6 the device can be applied to a smoke pipe already installedby This posicutting the same away as indicated and placing the device including portions Ild over the cut away portion of the smoke pipe and securing the same thereto by members 3!.

From the above description it is seen that applicant has provided a very simple and efiicient draft regulating device. The device acts automatically to secure the desired draft through the furnace and to check an excessive draft without permitting a large amount of air to pass from the furnace room up the chimney. The device can be nicely adjusted and is designed to take care of excessive drafts or pressures which might occur. The same has been amply demonstrated in. actual practice and found to be very successful and eflicient. The conduits ll] and 3t may of course be of any shape in cross section. Both cylindrical and rectangular conduits are commonly used.

It will, of course, be understood that various changes may be made in the form, details, ar rangement and proportions of the parts, without departing from the scope of applicants invention, which generally stated, consists in a device capable of carrying out the objects above set forth in the parts and combinations of parts disclosed and defined in the appended claims.

What is claimed is:

1. A draft regulator adapted to be used with a conduit through which gases pass from a furnace to a chimney having in combination, a casing having one end open, said end communicating directly with one side of said conduit so that said casing and conduit have a common passage, said casing having another end disposed Without said conduit, a vane disposed in said casing and swingable therein, said vane being'of such area that only a small amount of air may pass in said casing whereby an increased draft at the chimney end of said conduit will swing said vane toward said conduit and a damper disposed in said conduit and passage adjacent said first mentioned end of said casing movable with said vane and adapted to diminish the passage through said conduit as said vane is swung toward said conduit, said passage and damper being arranged to permit a back draft to pass into said casing and move said vane in a direction away from said conduit, said other end of said casing having an opening, a closure member for said opening having an aperture therethrough, means for adjusting the size of said aperture to regulate the sensitiveness of movement of said vane and resilient means holding said closure member in closed position whereby excessive back draft said vane may cause movement of said closure member.

A draft regulator for a conduit connecting a furnace to a chimney having in. combination, a casing disposed over said conduit having vertical side walls parallel to the longitudinal axis of said conduit and disposed adjacent the sides thereof, said casing having a vertical end wall, said casing being open at its bottom between said side walls and said conduit being open between said side walls so that a common passage is formed in said casing and conduit, a vane disposed in said casing being of such area that only a small amount of air can pass between it and the walls of said casing, said vane being pivoted about a horizontal axis adjacent the bottom of said end Wall and adjacent the top of said conduit, a damper plate secured to said vane and adapted to extend downwardly into said conduit at a small angle to the horizontal and toward the chimney end of said conduit and adjustable means for determining the normal position of said vane and damper plate about said axis, said vertical end Wall of said casing being movable outwardly and resilient means holding said end wall in normal position closing said casing whereby a strong back draftacting against said vane may force said vane away from said conduit and the air between said vane and end Wall move said .end wall outwardly.

ALBERT C. EKMAN. 

